• Georgia Institute Of Technology

• CS 6035

GT CS 6035: Introduction to Information Security

Project

Binary Exploitation!

Learning Goals of this Project:

Students will learn introductory level concepts about binary exploitation. This lab develops

understanding of control flow hijacking through different tasks/challenges designed to show

certain vulnerabilities or weaknesses in a C program. A python library pwntools will be used to

show some exploitation techniques and automation to successfully hack a program

The final deliverables:

A single json formatted file will be submitted to Gradescope. This file should be named

project_ctf.json. A template can be found in the Home directory.

See Submission Details for more information

Important Reference Material :

● If you’re an absolute beginner with no Linux experience,

○ This Writeup explaining some rudimentary basics of Computer Architecture

○ This Lecture I’m Developing on how the Stack and Function Calls work in C

● This Website may be able to help with some more basics from an external source

● This Intro to pwntools/pwndbg video showing how to automate some exploits and use

our exploit framework on the VM

● pwntools Documentation

● GDB command cheat sheet

Submission:

Gradescope (autograded) - see Submission Details

Virtual Machine:

(Note: downloads can be very slow when the project first releases due to very high traffic in the

first few hours/day)

- VM Download

- Username: cs6035, Password: pac-man-1980

GT CS 6035: Introduction to Information Security

00_intro

Step 1: Open a terminal and cd into the project directory project_ctf/00_intro.

$ cd ~/project_ctf/00_intro

Inspect the contents of the readme file

$ cat readme

Follow the instructions in the readme to modify e.py with your GTID (9 digit numeric school ID

number that looks like 901234567 and afterwards execute the script to get your first flag! Your

output will look like this. Copy this submission hash and place in the json file in your home

directory ~/project_ctf.json

SUBMIT YOUR FIRST FLAG TO MAKE SURE IT WORKS BEFORE

CONTINUING

Also, it is a very good idea to submit each flag you get to make

sure it works before moving on, in case of any issues

(Applicable for all flags): If for whatever reason you don’t get a

flag and you’re positive you should, try running the exploit once

or twice. The flag generator can have some unexpected

behaviors. When in doubt, make a post in Ed Discussion to ‘All

Instructors’ and we will assist you if possible

GT CS 6035: Introduction to Information Security

01_buffer_overflow_1

(watch the intro video first please, or if you want to try the experimental instruction

program BoxxY, see Appendix for details)

This task is a very simple buffer overflow that, upon inspection, will check if a variable is

non-zero. Using the information you have gathered from reading and the videos, it is your task

to get this program to get to the call_me() function, and get the flag printed.

Note: you are free to use GDB if you need to for this project but you need to run the program on

the command line (i.e. ./e.py) in order to get the real flag for submission and submit it!